Republican leaders are ramping up the pressure on President Barack Obama to justify his decision to delay health care reform's employer mandate for a year while keeping the individual mandate to purchase insurance in place.

In a letter to Obama, House Republican leaders and committee chairmen ask Obama a series of questions on how the delay in the employer mandate will affect the health insurance market next year. The questions include:

Will more individuals get government subsidies to purchase insurance on their own?

Will fewer employers offer insurance to their employees next year?

Will more people enroll in Medicaid?

Answers to these questions should be readily available since "the decision to delay the employer mandate was likely not a decision you made in only a day and necessarily required substantial review by analysts" at three agencies and the Office of Management and Budget, the letter states.

Officials from the Treasury Department and the Department of Health and Human Services have been asked to answer questions about their ObamaCare decisions at a July 18 hearing held by the House Energy and Commerce Committee.

Republicans also asked the president to "provide to Congress your justification for only delaying the employer mandate at this time and not the new mandate on individuals and families. We agree with you that the burden was overwhelming for employers, but we also believe American families need the same relief."

Under the Affordable Care Act, employers with 50 or more workers were required to provide insurance coverage to their employees by 2014 or pay a penalty to the government. The Obama administration last Wednesday extended that deadline to 2015, noting that employers had complained the reporting rules for enforcing this mandate needed to be simplified.

Then on Friday, the Obama administration announced it would not require health insurance exchanges in 2014 to verify consumers' eligibility for premium subsidies or their statements that they don't receive insurance from their employers. Republicans want the president to address whether this delay will lead to ineligible people getting government subsidies.

“The president’s decision to use the ‘honor system’ to hand out subsidies I think exposes taxpayers to massive fraud and abuse," said House Speaker John Boehner, R-Ohio, at a press conference today.

In their letter, Republicans argue that each delay in implementing the Affordable Care Act's provisions "continues to demonstrate that the entire law is unworkable."

"We agree with you that many of the provisions in the law cannot be implemented within the current time frame; but we strongly disagree with you that time will ever remedy these predictable consequences of the law," the letter states.

"If businesses can get relief from ObamaCare, the rest of America ought to be able to get relief as well," Boehner said.